Fiber distribution hub with outside accessible grounding terminals

ABSTRACT

The present disclosure relates to a telecommunications distribution hub having a cabinet that defines a primary compartment. The cabinet also includes one or more main doors for accessing the primary compartment. Telecommunications equipment is mounted within the primary compartment. The distribution hub further includes a secondary compartment that can be accessed from an exterior of the cabinet without accessing the primary compartment. A grounding interface is accessible from within the secondary compartment.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/900,129,filed Oct. 7, 2010, which is a continuation of application Ser. No.11/544,951, filed Oct. 6, 2006, now U.S. Pat. No. 7,816,602, whichapplication claims the benefit of provisional application Ser. No.60/783,818 filed Mar. 17, 2006, and is also a continuation-in-part ofapplication Ser. No. 11/354,286 filed Feb. 13, 2006, now U.S. Pat. No.7,720,343, which applications are incorporated herein by reference intheir entirety.

BACKGROUND

Passive optical networks are becoming prevalent in part because serviceproviders want to deliver high bandwidth communication capabilities tocustomers. Passive optical networks are a desirable choice fordelivering high-speed communication data because they may not employactive electronic devices, such as amplifiers and repeaters, between acentral office and a subscriber termination. The absence of activeelectronic devices may decrease network complexity and/or cost and mayincrease network reliability.

FIG. 1 illustrates a network 100 deploying passive fiber optic lines. Asshown, the network 100 can include a central office 101 that connects anumber of end subscribers 105 (also called end users 105 herein) in anetwork. The central office 101 can additionally connect to a largernetwork such as the Internet (not shown) and a public switched telephonenetwork (PSTN). The network 100 can also include fiber distribution hubs(FDHs) 103 having one or more optical splitters (e.g., 1-to-8 splitters,1-to-16 splitters, or 1-to-32 splitters) that generate a number ofindividual fibers that may lead to the premises of an end user 105. Thevarious lines of the network 100 can be aerial or housed withinunderground conduits.

The portion of the network 100 that is closest to central office 101 isgenerally referred to as the F1 region, where F1 is the “feeder fiber”from the central office 101. The portion of the network 100 closest tothe end users 105 can be referred to as an F2 portion of network 100.The network 100 includes a plurality of break-out locations 102 at whichbranch cables are separated out from the main cable lines. Branch cablesare often connected to drop terminals 104 that include connectorinterfaces for facilitating coupling of the fibers of the branch cablesto a plurality of different subscriber locations 105.

Splitters used in an FDH 103 can accept a feeder cable F1 having anumber of fibers and may split those incoming fibers into, for example,216 to 432 individual distribution fibers that may be associated with alike number of end user locations. In typical applications, an opticalsplitter is provided prepackaged in an optical splitter module housingand provided with a splitter output in pigtails that extend from themodule. The splitter output pigtails are typically connectorized with,for example, SC, LC, or LX.5 connectors. The optical splitter moduleprovides protective packaging for the optical splitter components in thehousing and thus provides for easy handling for otherwise fragilesplitter components. This modular approach allows optical splittermodules to be added incrementally to FDHs 103 as required.

It is common for F1 and F2 cables to be routed underground. Whenunderground construction or other activity is to be undertaken in areaswhere underground cables are buried, it is necessary to mark thelocations of the buried cables before the activity is undertaken. In thecase of shielded/armored cables, a field technician can transmit alocator signal (e.g., an RF signal) through the metal shielding of thecables, and then use an above ground sensor (e.g., an RF detector) todetect the signal along the length of the cable and thereby identify thelocation of the cable. As the cable is detected, the technician canapply a spray paint line to the ground surface so that the location ofthe underlying cable is identified. By marking the ground surface, thelikelihood for the cable to be broken or otherwise damaged during theunderground activity is reduced.

In the case of shielded/armored cables, the cables are preferablygrounded for safety. In a typical configuration, a grounding platehaving grounding pins is provided within the interior of a fiberdistribution hub cabinet. The shields of the F1 and F2 cables areelectrically connected to the pins of the grounding plate by wires. Oneof the pins is electrically connected to ground (e.g., a metal rod, postor other member driven into the ground). In this type of hubarrangement, for the field technician to mark the F1 and F2 lines, it isnecessary for the field technician to gain access to the interior of thecabinet. Once the cabinet is open, the technician can disconnect thecable of interest from ground and transmit the locator signal throughthe shielding of the cable. After the location of the cable has beenmarked, the shield of the cable is reconnected to ground.

Field technicians responsible for marking underground cable are oftennot employed by the service provider that owns and operates the fiberdistribution hub. Furthermore, field technicians responsible for markingcable are typically not trained with respect to the telecommunicationsequipment typically housed within a fiber distribution hub. Therefore,it can be undesirable for the field technician to have access to theinterior of the fiber distribution hub. Moreover, the cabling and othercomponents within a fiber distribution hub can often block access to thegrounding plate and/or make the grounding plate difficult to find.Therefore, it is desirable to have a fiber distribution hub having aconfiguration which allows a field technician to access the groundingplate without having to open the primary cabinet of the fiberdistribution hub.

SUMMARY

Certain aspects of the disclosure relate to fiber optic cable systems.

In example systems, a fiber distribution system includes one or morefiber distribution hubs (FDHs) that provide an interface between thecentral office and the subscribers.

Certain aspects of the disclosure relate to cable routingconfigurations.

Other aspects of the disclosure relate to enhanced access andscalability through the use of modular subscriber termination componentsand modular splitters.

Certain additional aspects of the present disclosure relate to fiberdistribution hub configurations that allow a field technician to quicklyand easily access grounding terminations of the fiber distribution hubwithout having to enter the interior of the main cabinet of the fiberdistribution hub. In certain embodiments, the cabinet of the fiberdistribution hub is provided with a secondary pocket or compartmentwhere the grounding terminations can be accessed. In certainembodiments, a grounding pin corresponding to a selected undergroundcable desired to be located is disconnected from the ground by merelyturning a nut mounted on the grounding pin a few turns.

A variety of additional inventive aspects will be set forth in thedescription that follows. The inventive aspects can relate to individualfeatures and to combinations of features. It is to be understood thatboth the forgoing general description and the following detaileddescription are exemplary and explanatory only and are not restrictiveof the broad inventive concepts upon which the embodiments disclosedherein are based.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a passive fiber optic network;

FIG. 2A is a front perspective view of an example fiber distribution hubhaving a cabinet with front doors shown in a closed position;

FIG. 2B is a front perspective view of the fiber distribution hub ofFIG. 2A with the cabinet doors shown in an open position;

FIG. 2C is a front perspective view of the fiber distribution hub ofFIG. 2A with a swing frame swung out of the cabinet;

FIG. 3 is a schematic diagram showing an example cable routing schemefor the fiber distribution hub of FIG. 2A;

FIG. 4 is a front perspective view of the swing frame of FIG. 2Cisolated from the fiber distribution hub;

FIG. 5 is a front side view of the swing frame of FIG. 4;

FIG. 6 is a right side view of the swing frame of FIG. 4;

FIG. 7 is a top view of the swing frame of FIG. 4;

FIGS. 8A-8C show one example of a splitter module of the distributionhub of FIG. 2A;

FIG. 9 shows an example splitter module having eight output fibersincluding connectorized ends secured to a storage module;

FIG. 10 depicts one example cable/fiber route from a splitter modulemounted on a swing frame to a storage module mounted on the swing frame;

FIG. 11 depicts on example cable/fiber route from a splitter modulemounted on a swing frame to a termination module mounted on the swingframe;

FIGS. 12A and 12B are front and rear perspective views of an exampletermination module of the distribution hub of FIG. 2A;

FIG. 13 is a rear perspective view of the swing frame of FIG. 4;

FIG. 14 is another perspective view of the swing frame of FIG. 4;

FIG. 15 is a left side view of the swing frame of FIG. 4;

FIG. 16 is a rear view of a swing frame including example interfacedevices and cable management devices mounted at the rear side of a swingframe;

FIG. 17 is a rear perspective view depicting one example configurationof interface devices and cable management devices on a swing frame;

FIG. 18 is a rear perspective view depicting another exampleconfiguration of interface devices and cable management devices;

FIG. 19 is a rear perspective view depicting yet another exampleconfiguration of interface devices and cable management devices;

FIG. 20 is a rear view of a fiber distribution hub cabinet having asecondary compartment or pocket for housing a cable grounding interface;

FIG. 21 is a front view of the fiber distribution hub of FIG. 20 withthe cabinet open and the swing frame pivoted out to show that thegrounding pins of the grounding interface project into the interior of amain compartment of the cabinet;

FIG. 22 is a perspective view of the secondary compartment of FIG. 20 inisolation from the main cabinet of the fiber distribution hub;

FIG. 23 is a cross sectional view taken along section line 23-23 of FIG.20;

FIG. 24 illustrates one side of an alternative secondary compartmentthat can be accessed from the backside of a telecommunications cabinet;

FIG. 25 illustrates an opposite side of the alternative secondarycompartment of FIG. 24;

FIG. 26 is a top view of the secondary compartment of FIG. 24;

FIG. 27 is a cross-sectional view taken along the 27-27 line of FIG. 26;

FIG. 28 is the cross-sectional view of FIG. 27 with grounding wiresextending into the secondary compartment and coupling to grounding postswithin the secondary compartment;

FIG. 29 is the cross-sectional view of FIG. 28, except one of thegrounding wires has been disengaged from one of the grounding posts;

FIG. 30 is a perspective view of an alternative swing frame;

FIG. 31 is a perspective view of yet another fiber distribution hub(FDH) with the swing frame swung out;

FIG. 32 is a front perspective view of the FHD of FIG. 31 with the toppanel and the swing frame removed to enable viewing of the interior ofthe FDH;

FIG. 33 is an exploded front, perspective view of the FDH of FIG. 31with the swing frame removed; and

FIG. 34 is a front, perspective view of the FDH of FIG. 31 with onetermination module and a frame member exploded from the swing frame.

DETAILED DESCRIPTION

Referring now to FIGS. 2-7, an example fiber distribution hub (FDH) 200in accordance with the principles of the present disclosure is shown.The FDH 200 includes a cabinet 201 that houses internal components. Thecabinet 201 includes openings through which a feeder cable (e.g., or F1cable) 700 and a subscriber cable 708 enter and exit the cabinet 201(see FIG. 2C). A swing frame 300 is pivotably mounted on hinges 355within the cabinet 201. The swing frame 300 includes bulkhead 301 thatdivides the swing frame 300 into a front portion 302 (see FIG. 4) and aback portion 304 (see FIG. 2C). The bulkhead 301 includes a main panel310 having a termination region 311 and a storage region 313. Generally,at least one termination module 400 (see FIGS. 13A and 13B) is providedat the termination region 311 and at least one storage module 600 (seeFIG. 9) is provided at the storage region 313. In some embodiments, thebulkhead 301 also includes a secondary panel 315 positioned adjacent themain panel 310 and configured for cable management. One or more feedercable interfaces 800 can be positioned within the rear portion of theswing frame 300. At least one splitter module housing 322 accommodatingone or more splitter modules 500 is positioned at the top of the swingframe 300.

FIG. 3 is a schematic diagram showing an example cable routing schemefor the FDH 200. The FDH 200 generally administers connections at atermination panel between incoming fiber and outgoing fiber in anOutside Plant (OSP) environment. As the term is used herein, “aconnection” between fibers includes both direct and indirectconnections. Examples of incoming fibers include the feeder cable fibersthat enter the cabinet and intermediate fibers (e.g., connectorizedpigtails extending from splitters and patching fibers/jumpers) thatconnect the feeder cable fiber to the termination panel. Examples ofoutgoing fibers include the subscriber cable fibers that exit thecabinet and any intermediate fibers that connect the subscriber cablefibers to the termination panel. The FDH 200 provides an interconnectinterface for optical transmission signals at a location in the networkwhere operational access and reconfiguration are desired. For example,as noted above, the FDH 200 can be used to split the feeder cables andterminate the split feeder cables to distribution cables routed tosubscriber locations. In addition, the FDH 200 is designed toaccommodate a range of alternative sizes and fiber counts and supportfactory installation of pigtails, fanouts and splitters.

As shown at FIG. 3, a feeder cable 700 is initially routed into the FDH200 through the cabinet 201 (e.g., typically through the back or bottomof the cabinet 201 as shown in FIG. 2C). In certain embodiments, thefibers of the feeder cable 700 can include ribbon fibers. An examplefeeder cable 700 may include twelve to forty-eight individual fibersconnected to a service provider central office 101. In some embodiments,after entering the cabinet 201, the fibers of the feeder cable 700 arerouted to a feeder cable interface 800 (e.g., fiber optic adaptermodules, a splice tray, etc.). At the feeder cable interface 800, one ormore of the fibers of the feeder cable 700 are individually connected toseparate splitter input fibers 702. The splitter input fibers 702 arerouted from the feeder cable interface 800 to the splitter modulehousing 322. At the splitter module housing 322, the splitter inputfibers 702 are connected to separate splitter modules 500, wherein theinput fibers 702 are each split into multiple pigtails 704, each havingconnectorized ends 706. In other embodiments, however, the fibers of thefeeder cable 700 can be connectorized and can be routed directly to thesplitter modules 500 thereby bypassing or eliminating the need for anintermediate feeder cable interface 800.

When the pigtails 704 are not in service, the connectorized ends 706 canbe temporarily stored on a storage module 600 that is mounted at thestorage region 313 of the swing frame 300. When the pigtails 704 areneeded for service, the pigtails 704 are routed from the splittermodules 500 to a termination module 400 that is provided at thetermination region 311 of the swing frame 300. At the termination module400, the pigtails 704 are connected to the fibers of a distributioncable 708. The termination panel is the dividing line between theincoming fibers and the outgoing fibers. A typical distribution cable708 forms the F2 portion of a network (see FIG. 1) and typicallyincludes a plurality of fibers (e.g., 144, 216 or 432 fibers) that arerouted from the FDH 200 to subscriber locations 709.

In some embodiments, one or more of the fibers of the feeder cable 700are not connected to any of the splitter modules 500. Rather, thesefibers of the feeder cable 700 are connected to pass-through fibers 712having connectorized ends 714. The pass-through fibers 712 are connectedto the termination modules 400, without first connecting to the splittermodules 500. By refraining from splitting a fiber 712, a stronger signalcan be sent to one of the subscribers. The connectorized ends 714 of thepass-through fibers 712 can be stored at the storage region 313 when notin use.

Referring back to FIGS. 2A-2C, the cabinet 201 of the FDH 200 includes atop panel 202, a bottom panel 203, a right side panel 204, a left sidepanel 206, a back panel 205, and at least one front door. In someembodiments, the at least one front door includes a right door 210 and aleft door 212. In one embodiment, the front doors 210, 212 include alock 211. The at least one front door is pivotally mounted to thecabinet 201 using hinges 214, 216 to facilitate access to the componentsmounted within the cabinet 201.

In general, the cabinet 201 of the FDH 200 is configured to protect theinternal components against rain, wind, dust, rodents and othercontaminants. However, the cabinet 201 remains relatively lightweightfor easy installation, and breathable to prevent accumulation ofmoisture in the unit. In some embodiments, an aluminum construction witha heavy powder coat finish also provides for corrosion resistance. Inone example embodiment, the cabinet 201 is manufactured from heavy gaugealuminum and is NEMA-4X rated. In other embodiments, however, othermaterials can also be used.

In accordance with example embodiments, the FDH 200 is provided in polemount or pedestal mount configurations. For example, as shown in FIG. 2,loops 218 can be provided on the cabinet 201 for facilitating deploymentof the cabinet 201 at a desired location. The loops 218 can be used toposition the cabinet using a crane. In particular, the crane can lowerthe cabinet 201 into an underground region. In some embodiments, theloops 218 are removable or can be adjusted to not protrude from the topcabinet panel 202.

Still referring to FIGS. 2B-2C, the swing frame 300 of the FDH 200includes a top panel 320, a bottom panel 330, a right side panel 340,and a left side 341. A hinge-mounting strip 350 is positioned at theleft side 341 of the swing frame 300. As depicted at FIG. 4, thebulkhead 301 further includes a connecting panel 319 that connects themain panel 310 to the hinge-mounting strip 350. As shown best at FIG. 4,a portion 325 of the secondary panel 315 extends upwardly past the toppanel 320 of the swing frame 300. The bulkhead 301 extends verticallybetween the top and bottom panels 320, 330, and laterally between theright side panel 340 and the left side 341.

In some embodiments, the hinge-mounting strip 350 of the swing frame 300is mounted to the cabinet 201 of the FDH 200 using one or more hinges355. The hinges 355 enable the entirety of the swing frame 300,including the termination modules 400, the storage modules 600, thefeeder cable interface device 800, and the splitter modules 500, to beswung out of the front doors 210, 212 of the cabinet 201 to enableaccess to optical components in the rear portion 304 of the swing frame300 for cleaning, testing, maintenance, additions, etc. Pivoting theswing frame 300 out of the cabinet 201 causes the right side panel 340of the swing frame 300 to move away from the interior volume of thecabinet 201. In some example embodiments, the swing frame 300 can bepivoted ninety degrees or more out of the cabinet 201.

In some embodiments, the hinges 355 of the swing frame 300 arepositioned to provide a single point of flex for the fiber cable routedto the swing frame 300. This hinge point is constructed to control thefiber bend. In particular, the hinges 355 and cable management devices,which are discussed in greater detail herein, are designed to ensurethat manufacture recommended bend radii are maintained when the swingframe 300 is opened or closed. In one embodiment, the cabinet 201 can beconfigured at a factory, or plant, so as to have cable bundles dressedaround the hinges 355. Preconfiguring the cabinet 201 reduces the chancethat cabling will be done incorrectly.

When the swing frame 300 is in the open position, as shown in FIG. 2C,components in the rear portion 304 of the swing frame 300 areaccessible. For example, a rear side of the main panel 310 and a rearside of the secondary panel 315 are accessible. In addition, thesplitter modules 500 located in the splitter module housing 322 (seeFIG. 4) are accessible through the open top of the swing frame 300 whenthe swing frame 300 is swung out of the cabinet 201. In contrast, whenthe swing frame 300 is in the closed position (see FIG. 2B), onlycomponents on the front portion 302 of the swing frame 300 are readilyaccessible.

In example embodiments, the swing frame 300 includes a release latch(not shown) that locks the swing frame 300 in a closed position withinthe cabinet 201 of the FDH 200 until the latch is actuated. Once thelatch is actuated, the swing frame 300 can be pivoted out of the cabinet201. In addition, a pivoting locking member (not shown) can be mountedto rear side 304 of the swing frame 300 to hold the swing frame 300 inthe open position.

Referring to FIGS. 4-5, the storage region 313 of the swing frame 300 islocated below the termination region 311. In other embodiments, however,the storage region 313 can be above or adjacent to the terminationregion 311. In general, the termination region 311 defines at least onerectangular opening 312 through which adapters 450 (see FIGS. 13A-13B)from a termination module 400 extend. The termination modules 400 aredescribed in greater detail herein. In the embodiment shown in FIG. 4,the termination region 311 includes two columns of openings 312 witheach column including twelve elongated slots. Strips 309 separate theopenings 312 of each column and provide surface area for adheringlabeling information (e.g., connector designation). The storage region313 also defines one or more openings 314 into which storage modules 600(see FIG. 9) are mounted. The storage modules 600 are described ingreater detail herein.

The bulkhead 301 bifurcates the bottom panel 330 into a front portion331 (see FIG. 4) and a rear portion 336 (see FIGS. 2C and 14). Ingeneral, the front portion 331 of the bottom panel 330 projectsforwardly from the bulkhead 301. In some embodiments, the front portion331 is further divided into a first front portion 332 and a second frontportion 334. Each front portion 332, 334 includes a flange 333, 335,respectively, that protrudes substantially perpendicular from the bottompanel 330. The front portion 331 of the bottom panel 330 thereby forms atrough configured to retain slack or excess fiber from the storageregion 313 or from the secondary panel 315. Edge 337 of the first frontportion 332 is angled to allow the swing frame 300 to pivot open withoutinterference from the trough.

As best shown in FIGS. 4 and 6, the bulkhead divides the side panel 340into front and rear flanges 342, 344, respectively. The front flange 342extends forwardly from the secondary panel 315 and the rear flange 344extends rearwardly from the secondary panel 315. The rear flange 344extends from the bottom panel 330 to a bend limiter 962 extending fromthe top panel 320. The front flange 342 extends from the bottom panel330 past the top panel 320 to the protruding portion 325 of thesecondary panel 315. In some embodiments, the front flange 342 includesa forward portion 344 substantially parallel to the rear flange 344 andan angled portion 343 extending between the protruding portion 325 ofthe secondary panel 315 and the forward portion 344.

As best shown in FIG. 7, the top panel 320 of the swing frame 300 issubstantially rectangular. The top panel 320 includes front and backedges 326, 327. Flanges 323, 324 (see FIG. 4) protrude upward from theedges 326, 327, respectively. The top panel 320 also has a first end 328adjacent side 341 and a second, opposite end 329 adjacent the side panel340. A bend radius limiter 940 extends upward from the first end 328. Insome embodiments, a portion of the end 329 of the top panel 320 definesa width of a channel B with the front flange 342 of the side panel 340.The portion of the end 329 defining the channel B terminates beforereaching the remaining portion of the end 329. The depth of the channelB extends from the secondary panel 315 to the flange 335 of the secondfront portion 33 of the bottom panel 330.

The splitter module housing 322 of the FDH 200 is positioned on the toppanel 320 adjacent the first end 328. The splitter module housing 322serves to protect, organize, and secure the splitter modules 500 of theFDH 200. The splitter module housing 322 can be constructed in varioussizes to accommodate different numbers of splitter modules 500. Thesplitter module housing 322 is generally rectangular and defines one ormore locations within the open interior sized to accept one or moreoptical splitter modules 500. To accommodate the splitter modules 500,the module housing 322 includes structure for supporting/securing thesplitter modules 500. In example embodiments, the splitter modules 500are designed to snap into the splitter module housing 322. In oneembodiment, the splitter modules 500 are loaded into the splitter modulehousing 322 from front to back (i.e., from the side facing end 329 tothe side facing end 328). The module housing 322 is further configuredto enable the splitter modules 500 to receive an input fiber, such asfiber 702 of FIG. 3, on one end of the splitter module 500 and to outputmultiple fibers, such as pigtails 704 of FIG. 3, from the opposing endof the splitter 500.

Referring now to FIGS. 8A-8C, one type of splitter module 500 that canbe mounted in the splitter module housing 322 is a splitter having anintegral connector. FIG. 8A is a left side view of such a splittermodule 500. The splitter module 500 includes a housing 505 having atleast one protective boot 510 protruding frontwardly and at least oneintegral connector 520 protruding rearwardly. In the embodiment shown,two boots 510 protrude from the front and two integral connectors 520protrude rearwardly from the splitter housing 505. In one exampleembodiment (not shown), each splitter has four integral connectors 520.In some embodiments, a handle 540 also protrudes from the front end ofthe splitter housing 505. FIG. 8B is an exploded view of the splittermodule 500 of FIG. 8A showing the internal components of the splittermodule 500.

FIG. 8C shows a cross-section of the splitter module 500 of FIG. 7Ainserted in the splitter module housing 322. An adapter assembly 530 issecured to the splitter module housing 322 using a fastener 536. In oneembodiment, adapter assemblies 530 are mounted at the backside of thesplitter module housing 322. The adapter assembly 530 is configured toreceive the connectors 520 of the splitter module 500 when the splittermodule 500 is inserted into the splitter module housing 322. As shown,the adapter assembly 530 is further configured to receive an opposingconnector associated with the feeder cable 700. In some embodiments, theadapter assembly 530 receives a connector 703 terminating a splitterinput fiber 702. In other embodiments, the adapter assembly 530 receivesa connector 701 terminating the feeder cable 700 itself. In this way,the feeder cable fibers 700 can be readily coupled to the splittermodules 500.

Other embodiments of splitter modules 500 do not include integralconnectors 520. In such embodiments, adapter assemblies 530 are notmounted at the splitter module housing 322 and the feeder cables 700cannot be plugged directly into the splitter modules 500. Rather, inputpigtails (not shown) pass through the splitter housing 505 and enter thesplitter module 500. The opposing ends of the input pigtails can beconnectorized or unconnectorized. If the ends 701 terminate inconnectors (not shown), then the input fibers 702 are interfaced withthe feeder cable 700 using an adapter module 810 (see FIG. 18). If theends 701 are unconnectorized, then the input fibers 702 are spliced withthe feeder cable 700 using a splice tray 808 (see FIG. 19).

Typically, each splitter module 500 receives between one and four fibersand outputs between two and sixteen fibers 704 for every input fiber. Inone example embodiment, four input fibers 702 enter a splitter module500 and thirty-two pigtail fibers 704 exit the splitter module 500.Further information regarding the splitter module 500 can be found inU.S. patent application Ser. No. 11/354,297, filed Feb. 13, 2006,entitled “Fiber Optic Splitter Module”, which is hereby incorporated byreference. Additional information on other types of splitter modules canbe found at U.S. application Ser. No. 10/980,978, filed Nov. 3, 2004,entitled “Fiber Optic Module And System Including Rear Connectors;” U.S.application Ser. No. 11/138063, filed May 25, 2005, entitled “FiberOptic Splitter Module;” U.S. application Ser. No. 11/215,837, filed Aug.29, 2005, entitled “Fiber Optic Splitter Module With Connector Access;”and U.S. application Ser. No. 11/321,696, filed Dec. 28, 2005, entitled“Splitter Modules For Fiber Distribution Hubs,” the disclosures of whichare hereby incorporated by reference.

Referring now to FIGS. 9-10, the splitter modules 500 and storagemodules 600 can be incrementally added to the swing frame 300. FIG. 9illustrates a splitter module 500 having multiple connectorized pigtails704 exiting from a protective boot 510 on the splitter module 500. Theconnectorized pigtails 704 are typically stored in one or more storagemodules 600 prior to installation on the swing frame 300. In someembodiments, the connector 706 of each pigtail 704 is secured in astorage module 600 before the splitter module 500 leaves the factory.Typically, the connectorized pigtails 704 of each splitter module 500are routed to four storage modules 600 each holding eight connectors.

The storage module 600 includes a body 610 having a front side 602 and arear side 604. The body 610 is configured to hold at least one fiberconnector 706. Typically, the body 610 is configured to hold about eightconnectors 706. In some embodiments, the body 610 is arranged to retainthe fiber connectors 706 in a single row configuration. In otherembodiments, the body 610 can be arranged to hold the connectors 706 ina square pattern or in any other desired configuration. More informationregarding the storage modules 600 can be found in U.S. application Ser.No. 10/610,325, filed on Jun. 30, 2003, entitled “Fiber Optic ConnectorHolder and Method”; U.S. application Ser. No. 10/613,764, filed on Jul.2, 2003, entitled “Telecommunications Connection Cabinet;” and U.S.application Ser. No. 10/871,555, filed on Jun. 18, 2004, entitled“Multi-position Fiber Optic Connector Holder and Method,” thedisclosures of which are hereby incorporated by reference.

In some embodiments, the body 610 is designed to snap into one of theopenings 314 defined in the storage region 313 of the main panel 310.The openings 314 can be arranged in any desired configuration within thestorage region 313 of the main panel 310. In the example shown in FIG.10, the storage region 313 of the main panel 310 defines nine openings314 in a rectangular pattern. Each opening 314 is configured to receivea storage module body 610 arranged to retain eight fiber connectors 706in a row.

As shown in FIG. 10, when the splitter module 500 is loaded into thesplitter module housing 322 during installation, the correspondingstorage modules 600 are loaded onto the storage region 313 of the mainpanel 310. For ease in viewing, only one splitter 500 having one pigtail704 and one storage module 600 is illustrated. The pigtail 704 extendingfrom the splitter module 500 to the storage module 600 is routed fromthe protective boot 510, across the top panel 320, down through thechannel B on the front side of the secondary panel 315, and across thebottom panel 330 of the swing frame 300.

To accomplish this routing, the top panel 320 and secondary panel 315include cable management arrangements. In some embodiments, the cablemanagement arrangements on the top panel 320 include a first spool 952positioned between the splitter housing 322 and the bend radius limiter962 and a second spool 954 positioned between the bend limiter 940 andthe front flange 342. Pigtails 704 output from the splitter 500 arefirst wrapped around the first spool 952 and then around the secondspool 954.

A bend radius limiter 964 having tabs 965 and extending downward fromthe top panel 320 partially defines the channel B. From the second spool954, some of the pigtails 704 are routed over the bend limiter 964 andinto the channel B. In some embodiments, a partial fiber spool 966 ismounted to extend from the protruding portion 325 of the secondary panel315 and is also oriented to route fiber into the channel B. To avoidexcessive weight or entanglement of the fibers 704, some of the fibers704 can be routed into channel B over the partial spool 966 instead ofbend limiter 964. Extra slack can also be taken up by routing thepigtails 704 over spool 966 instead of over bend limiter 964. A bendlimiter 968 can also be mounted on the protruding portion 325 of thesecondary panel 315 and oriented to route fiber up to the partial spool966.

The front of the secondary panel 315 includes at least one row ofpartial spools 970 and at least one row of radius limiters 980. In oneexample embodiment, the partial spools 970 are oriented to enable fiberrouted down channel B to wrap at least partially around one of thespools 970. The fiber can travel from the partial spools 970 eitheralong the bottom panel 330 to the storage modules 600 or over thelimiters 980 to the termination modules 400. The limiters 980 areoriented to enable fiber routed from the partial spools 970 to travel tothe termination modules 400 without excessive bending.

Referring now to FIG. 11, when a pigtail 704 retained in a storagemodule 600 should be connected to a subscriber distribution line 708,the corresponding connector 706 is removed from the storage module 600and transferred to the appropriate adapter 450 on a termination module400. During this transfer process, the fiber may need to be rewoundaround a different partial spool 970, such as partial spool 972, inorder to reach the adapter 450. From the partial spool 972, the fibercan be routed around a suitable limiter 980 to avoid excessive bendingbefore reaching the adapter 450. In some embodiments, the fiber is alsofed through support fingers 990 extending from the termination section311 of the main panel 310 before plugging into the adapter 450. When allof the fibers 704 originally secured in the storage module 600 have beenrouted to subscriber termination modules 400, the empty storage modules600 can be removed to make room for a new splitter module 500 and newstorage modules 600.

Referring now to FIGS. 12A-12B, as time passes and the number ofsubscribers increases, a user can add termination modules 400 to theswing frame 300. FIGS. 12A and 12B show one example of a terminationmodule 400. The termination module 400 includes a termination leg 410and a management leg 420 arranged in a substantially L-shapedconfiguration. In some embodiments, a linking section 430 connects thetermination leg 410 to the management leg 420. In other embodiments, thelinking section 430 is monolithically formed with either the terminationleg 410 or the management leg 420. In still other embodiments, thetermination leg 410, the management leg 420, and the linking section 430are monolithically formed (e.g., are constructed as a single piece ofbent sheet metal).

In some embodiments, a front side of the termination leg 410 of thetermination module 400 (shown in FIG. 12B) mounts to the rear side ofthe main panel 310. In one embodiment, the termination leg 410 mounts tothe main panel 310 using screws 417. In other embodiments, however,other fasteners such as bolts, rivets, nails, and other such devices canbe used to connect the module 400 to the main panel 310. In still otherembodiments, the module 400 can be attached to the main panel 310 usingadhesive.

Each termination module 400 includes at least one row of fiber opticadapters 450 for connecting the fibers of the main cable 700 to thefibers of the distribution cable 708. Each adapter 450 has a front end452 and a rear end 454. The front end 452 of each adapter 450 isconfigured to retain a connector 714 of a fiber 712 interfaced with themain line 700, or the connector 706 of a fiber 704 split from the mainline 700. The rear end 454 of each adapter 450 is configured to retain aconnector 710 of a fiber of the distribution cable 708. The adapters 450protrude through the termination leg 410 so that the connectors 706enter the front ends 452 of the adapters 450 from a front side of themain panel 310 and the connectors 710 of the distribution cable 708enter the adapters 450 from a rear side of the main panel 310.

In the depicted embodiment, each module 400 includes six horizontal rowsof adapters 450 that cooperate to define two side-by-side banks ofadapters. When the module 400 is mounted to the main panel 310, thefront side of the leg 410 abuts against the backside of the main panel310, and the rows of adapters 450 project forwardly through thecorresponding horizontal slots 314 defined by the panel 310.

The management leg 420 extends rearwardly from the termination leg 410.Each management leg 420 includes an appropriate number of fanouts 424 toaccommodate the number of adapters 450 on the module 400. For example,in one embodiment, the termination leg 410 of a module 400 includes sixrows of adapters 450, each row having twelve adapters 450, and themanagement leg 420 includes six 12:1 fanouts 424. As the term is usedherein, a 12:1 fanout is a fanout configured to receive twelve opticalfibers and to output a single cable ribbon containing the twelve fibers.In another embodiment, nine 8:1 fanouts or three 24:1 fanouts could beprovided instead of the 12:1 fanouts. In still other embodiments,fanouts can be used to upjacket the fiber.

In some embodiments, the termination module 400 is precabled at thefactory to include a connectorized distribution fiber 708 coupled toeach adapter 450. Dust caps 453 are generally provided on the front ends452 of the adapters 450 to protect the terminated distribution fibers708 from dust, dirt, and other contaminants. The connector 710 of eachdistribution fiber 708 is mounted within the rear end 454 of an adapter450 and the distribution fibers 708 are routed from the connector 710 tothe fanouts 424 provided on the management leg 420 of the terminationmodule 400. In still other embodiments, the termination module 400 isnot precabled and dust caps 455 are also provided on the rear ends 454of the adapters 450 to protect the adapters 450.

In some embodiments, the management leg 420 of the termination module400 also includes at least one cable management device 425 for managingexcess fiber length of the distribution fibers 708. Generally, in suchsystems, the fibers 708 are routed first to the cable management device425 and then to the fanouts 424. Examples of cable management devices425 include a fiber spool, one or more radius bend limiters, one or morefiber clips, and other such devices. In the example shown, themanagement leg 420 includes a fiber spool 426 formed from two radiusbend limiters. Each radius bend limiter includes a flange 427 forretaining the fiber on the spool 426. In some embodiments, one or morefiber cable clips 428 for retaining fiber cables can be spaced betweenthe radius bend limiters of the spool 426.

Referring now to FIG. 13, the management leg 420 of the terminationmodule 400 includes an opening 422 through which the fibers are routedfrom the cable management devices 425 to the fanouts 424. Upon exitingthe fanouts 424, the ribbon fibers are routed to a cabinet fanout (notshown) or other cable interface device. In other embodiments, thefanouts 424 are provided on the same side of the management leg 420 asthe cable management device 425. In such embodiments, the ribbon fibersare routed from the fanouts 424 through the openings 422 and to thecabinet fanout. The cabinet fanout is mounted to the interior of thecabinet 201 and is not attached to the swing frame 300. The cabinetfanout can be used to reduce the ribbon fibers into a single jacketedstub cable that exits the FDH 200. The stub cable is spliced to asubscriber distribution cable outside of the FDH 200. In variousembodiments, the stub cable ranges in length from about 25 feet to about300 feet. In other embodiments, the distribution cable 708 can be routedinto the cabinet 201 and spliced or otherwise connected to the fiber708.

Referring now to FIG. 14, the rear side 304 of the swing frame 300 formsan open chamber adapted to house at least one termination module 400.The open chamber is defined by the bulkhead 301, the top panel 320, thebottom panel 330, and the side panel 340. FIG. 14 is a rear perspectiveview of four termination modules 400 mounted in the open chamber. Theadapters 450 have been removed for ease in viewing. In otherembodiments, any desired number of termination modules 400 can bemounted on the swing frame 300. The termination modules 400 areconfigured to mount to the rear side of the termination region 311 ofthe main panel 310.

FIG. 15 shows a left side view of a swing frame 300 having fourtermination modules 400 mounted therein. When multiple terminationmodules 400 are mounted to the rear side of the main panel 310, themanagement legs 420 of the termination modules 400 form a partial sidepanel opposing the side panel 340. In some embodiments, the managementlegs 420 of the modules 400 are secured to one another or to the swingframe 300. In other embodiments, shown in FIG. 15, the modules 400 aresecured to the swing frame 300 only at the termination leg 410 and themanagement legs 420 are free floating.

Referring now to FIGS. 16-19, the swing frame 300 can be configured withdifferent interface devices 800 (see FIG. 3) and cable managementdevices to create multiple fiber pathways between the incoming feedercable 700 and the distribution lines 708. The interface devices 800 andmanagement devices used in a particular configuration will depend onwhether it is desirable to split the feeder cable 700 and what type ofsplitter module 500 is utilized.

In some embodiments, the feeder cable 700 connects to one or moresplitter input fibers 702. In one such embodiment, a first end 701 of asplitter input fiber 702 is connectorized. In another such embodiment,the first end 701 is unconnectorized. The opposite end 703 of the inputfiber 702 can either interface with an integral connector 520 on thesplitter module 500, such as when using the splitter module depicted inFIGS. 8A-8C, or can penetrate the splitter housing 505. In otherembodiments, however, the feeder cable 700 has connectors configured tointerface with integral connectors 520 of the splitter module 500.

FIG. 16 is a rear view of the swing frame 300 adapted to interface aconnectorized feeder cable 700 with a splitter module 500. To accomplishthis interface, the cable management devices are arranged according to aconfiguration C1. In configuration C1, a cable storage spool 922 and oneor more partial storage spools 924 are mounted to the side panel 340 ofthe swing frame 300. A fanout device 926 is mounted adjacent the spools922, 924. A radius limiter 936 is mounted from the secondary panel nearthe corner formed by the top panel 320 and side panel 340. Supportfingers 932 projecting downward from the top panel 320 form a path Aalong which fibers can be routed from one end 329 of the top panel 320to the other end 328. In some embodiments, the support fingers 932include a multi-pronged clip 934 having at least two fingers 932, eachfinger 932 extending in a different direction. In one exampleembodiment, the multi-pronged clip 934 includes four fingers 932positioned orthogonally relative to one another. Any excess fiber lengthcan be taken up by winding the pigtails 702 around the multi-prongedclip 934. A limiter 940 having tabs 945 extends from the top panel.

To connect the feeder cable 700 to the splitter 500, the cable 700 isfirst routed around spools 922, 924 and then to the fanout device 926.The fanout device 926 separates the fibers of the feeder cable 700 intoindividual input fibers. Any excess length of the individual fibers ofthe feeder cable 700 can be stored by wrapping the fibers around thespools 922, 924. The fibers of the feeder cable 700 are next routedaround the limiter 936 and along the path A using the support fingers932 projecting downward from the top panel 320. The feeder cable 700 isnext curved around the limiter 940 extending from the top panel 320 andplugged directly into at least one of the adapter assemblies 530 securedto the splitter module housing 322. The fibers of the feeder cable 700can be protected while being routed within the swing frame 300 by loosebuffer tubes.

FIG. 17 is a rear perspective view of the swing frame 300 adapted tointerface a connectorized feeder cable 700 to a splitter module 500. Thecable management devices are arranged according to a variation ofconfiguration C1. The storage spools 922, 924 and fanout device 926 aremounted to the rear side of the secondary panel 315 rather than the sidepanel 340. In other embodiments (not shown), the storage spools 922, 924and fanout device 926 could be mounted to the bottom panel 330.Regardless of the location of the spools 922, 924 and fanout device 926,the feeder cable 700 is still routed from the fanout device 926 to thebend limiter 936, along path A, over the bend limiter 940 and to theadapter assembly 530 mounted on the splitter module housing 322.

Referring now to FIGS. 18-19, the feeder cable 700 can be interfacedwith splitter inputs 702 using at least one interface device 800 ratherthan connecting directly to the splitter 500. FIG. 18 is a rearperspective view of the swing frame 300 configured to interface aconnectorized feeder cable 700 with a splitter module 500 throughintermediate splitter input fibers 702. Each splitter input fibers 702has a first connectorized end 703 that plugs into one of the adapterassemblies 530 opposite the integral connectors 520 of the splitters500. In other embodiments not using a splitter having an integralconnector, however, the splitter input 702 is a pigtail that penetratesthe splitter housing 505 rather than plugging into an adapter assembly530. Each splitter input fibers 702 also has a second connectorized end701 that interfaces with a connectorized end of a fiber of the feedercable 700.

Such input pigtails 702 are routed from the adapter assembly 530 overthe bend radius limiter 940 and underneath the top panel 320 as shown inFIG. 16. In particular, the input pigtails 702 are routed along the pathA towards the side panel 340 using the support fingers 932 and thenaround the radius bend limiter 936. The ends 701 of the input pigtailsare then connected to the feeder cable 700 using a first adapter module820. In some embodiments, the first adapter module is mounted to thesecondary panel 315 adjacent the bottom panel 330. In other embodiments,however, the first adapter module 820 can be secured to the bottom panel330 or the side panel 340. The first adapter module 820 includesmultiple adapters 825 arranged in one or more rows. In some embodiments,each row includes about six adapters 825. Additional informationregarding the adapter module 820 can be found in U.S. application Ser.No. 11/095,033, filed Mar. 31, 2005, and entitled “Adapter BlockIncluding Connector Storage;” and U.S. Pat. Nos. 5,497,444; 5,717,810;5,758,003; and 6,591,051, the disclosures of which are herebyincorporated by reference.

In order to connect the feeder cable 700 to the first adapter module820, additional cable management devices are provided according to asecond configuration C2. The second configuration C2 includes a fanoutdevice 901 and one or more full or partial slack storage fiber spools902, 904, respectively. In the example shown, the fanout device 901 andstorage spools 902, 904 are mounted to the bottom panel 330.

The feeder cable 700 is first routed to the fanout device 901, whichseparates the fibers of the ribbon cable 700 into individual fibers. Anyexcess length of the individual fibers of the feeder cable 700 can bestored in the slack storage spool 902 and partial slack storage spools904. The fibers of the feeder cable 700 are next routed to the firstadapter module 820. The connectorized ends of the feeder cable 700 aremounted into one end of the adapters 825 of the first adapter module820. The connectorized ends 701 of the input fibers 702 are routed fromthe radius limiter 936 to the opposite end of the adapters 825 of thefirst adapter module 820. The adapters 825 provide an interface betweenthe connectors of the feeder cable fibers 700 and the connectors 701 ofthe input fibers 702.

FIG. 19 is a rear perspective view of the swing frame 300 configured foruse with a splitter module and a feeder cable 700 having unconnectorizedends. The feeder cable 700 is spliced to splitter input fibers 702having unconnectorized second ends 701. In order to connect the feedercable 700 to the unconnectorized fiber inputs 702, a splice tray 830 isprovided at the rear side 304 of the swing frame 300.

In order to connect the feeder cable 700 to the splice tray 830,additional cable management devices are provided according to a thirdconfiguration C3. The third configuration C3 includes a fanout device907 and one or more radius bend limiters 906 mounted around the splicetray 830. Additionally, at least one radius bend limiter 908 ispositioned adjacent the splice tray 830. Each limiter 906 includes a tab907 to maintain the fibers in a loop around the limiters 906. Thelimiters 906 are oriented to prevent fiber from catching on the cornersof the splice tray 830. In some embodiments, the splice tray 830 andlimiters 906 are positioned on the back of the secondary panel 315. Inother embodiments, however, the splice tray 830 and limiters 906 can bepositioned in any desired location at the rear side 304 of the swingframe 300.

The unconnectorized ends of the feeder cable 700 are routed around thelimiters 906 and to the splice tray 808. Any excess length of theindividual fibers of the feeder cable 700 can be stored by wrapping thefibers around the splice tray 830. The input fibers 702 from thesplitter module 500 are routed from the radius limiter 936 around thelimiter 908 and into the splice tray 830. The unconnectorized ends ofthe feeder cable 700 are then spliced with the unconnectorized ends 701of the input fibers 702.

Still referring to FIGS. 16-19, in some embodiments, it may be desirablenot to split one or more of the feeder cables 700 to enable transmissionof a stronger or more reliable signal to a subscriber. In someembodiments, therefore, the swing frame 300 is further configured toenable at least one fiber (referred to as a pass-through fiber) 712 tointerface with a fiber from the feeder cable 700. The pass-through fiber712 bypasses the splitter modules 500 and proceeds to the front of theswing frame 300 to interface with a distribution line 708.

To accomplish such a routing, the swing frame 300 includes an opening910 in the rear flange 344 of the side panel 340. In some embodiments,the opening 910 includes a radius limiter 912 (best seen in FIG. 13)extending outward from the outside surface of flange 344 to preventexcessive bending of a fiber routed through the opening 910. A tab 915can also be pressed outward in rear flange 344 to define a channel upthe outer side of the rear flange 344. A radius bend limiter 962 linksthe rear flange 344 of the side panel 340 to the top panel 320.Additional cable management devices are provided based on theconfiguration C1, C2, C3 with which the swing frame 300 is set up.

Referring to FIG. 17, if the swing frame 300 is arranged according toconfiguration C1, then the connectorized fibers of the feeder cable 700are connected to the input fibers 702 using a second adapter module 810.The adapter module 810 includes multiple fiber optic adapters 815configured to accept connectorized fibers from either end. The swingframe 300 also includes additional cable management in the form of abend radius limiter 906 and slack storage spools 902, 904.

To bypassing the splitter modules 500, the feeder cable 700 is stillrouted around spools 922, 924 to the fanout device 926. From the fanoutdevice 926, however, the feeder cable fibers 700 are routed back aroundspools 922, 924, around bend limiter 926 and then around spools 902,904. From the spools 902, 904, the connectorized ends of the fibers 700are secured to the adapter module 810. The adapter module 810 connectsthe fibers 700 with connectorized ends of pass-through fibers 712 thatare routed out the opening 910, up the side panel 340, over the limiter962, and onto the top panel 320. From the top panel 320, thepass-through fibers 712 are routed towards the termination modules 400as described above with reference to FIGS. 10 and 11.

Referring to FIG. 18, pass-through fibers 712 can also be used with thesecond configuration C2. The feeder cable 700 is still routed first tothe fanout device 901 and then to one end of the adapter module 820 withany slack being stored in spools 902, 904. However, instead of splitterpigtails 702 connecting to the other end of the adapter module 820, thepass-through pigtails 712 are plugged into the adapter module 820. Thepass-through pigtails 712 then follow the same routing pattern asdiscussed in the previous paragraph.

Referring to FIG. 19, the pass-through pigtails 712 can also be splicedto unconnectorized ends of the feeder cable 700. If such a configurationis desired, then the swing frame 300 is provided with the second adaptermodule 810 discussed above with reference to FIG. 17. The feeder cable700 is still routed around limiters 906 and up to the splice tray 830according to the configuration C3. Any excess length of the individualfibers of the feeder cable 700 can be stored by wrapping the fibersaround the limiters 906. However, the fibers of the feeder cable 700 arespliced to connectorized pigtails 711 rather than to the splitter inputs702. From the splice tray 830, the connectorized pigtails 711 are routedaround the storage spools 902, 904 and then plugged into the secondadapter module 810. The second adapter module 810 connects the pigtails711 with the pass-through connectorized fibers 712 that are routed outof the opening 910, up the side panel 340 to the limiter 962, and ontothe top panel 320.

The pass-through fibers 712 bypass the splitter module 500 and arerouted around the second fiber spool 954 of the top panel 320 and intothe channel B via either the limiter 964 or the partial spool 966. Therouting of the pass-through fiber 712 along the front side 302 of theswing frame is substantially the same as the routing of the splitterpigtails 704 discussed above with reference to FIGS. 10 and 11.Typically, a pass-through fiber 712 is immediately connected to asubscriber line 708 via an adapter 450 on a termination module 400. Insome embodiments, however, the pass-through fibers 712 can be stored inempty locations on the storage modules 600.

FIGS. 20-29 show alternative fiber distribution hubs (FDH) havingfeatures in accordance with the principles of the present disclosure.One example FDH 200′ is shown in FIGS. 20-23. The fiber distribution hub200′ includes a cabinet 201′ housing the same components previouslydescribed with respect to the fiber distribution hub 200. For example,the cabinet 201′ defines a primary compartment 230 that can be accessedby opening front doors 210, 212. Swing frame 300 is pivotally mountedwithin the primary compartment 230. A termination region and a storageregion are provided on the swing frame. Splitters are also provided onthe spring frame. Further details regarding the internal components ofthe primary compartment 230 can be found by referring to the detaileddescription pertaining to the fiber distribution hub 200.

The fiber distribution hub 200′ has been modified to include a secondarycompartment 232 that can be accessed from the backside of the cabinet201′. The secondary compartment 232 can also be referred to as a pocket,recess, inset region, chamber, or like terms. The secondary compartment232 can be accessed by opening a secondary door 234. The secondary door234 is located on the outside of the cabinet 200′. When the secondarydoor 234 is open, access is provided to the secondary compartment 232,but no access is provided to the primary compartment 230 of the cabinet201′. Therefore, a field technician can quickly find and enter thesecondary compartment 232 without disturbing any of the internaltelecommunications components of the fiber distribution hub 200′.

Referring to FIG. 22, the secondary compartment 232 is defined by aplate 235 having a mounting flange portion 237 and an enclosure portion239. The mounting flange portion 237 extends around the perimeter of theenclosure portion 239. The enclosure portion 239 projects rearwardlyfrom the mounting flange portion 237 and defines a generally rectangularrecess that forms the secondary compartment 232. The secondary door 234is shown pivotally connected to the plate 235 by a hinge 240. Thesecondary door 234 can be secured in a closed position by anyconventional latching arrangement. In one embodiment, the secondary door234 can be held in a closed position by a bolt (not shown) that extendsthrough opening 242 and threads into a fixed nut (not shown) securedwith an opening 244 of the plate 235.

As shown best at FIG. 20, the plate 235 mounts to a back wall 246 of thecabinet 201′. The back wall 246 of the cabinet 201′ has an opening 248for receiving the enclosure portion 239 of the plate 235. To mount theplate 235 to the back wall 246, the enclosure portion 239 is insertedthrough the opening 248 and the mounting flange portion 237 of the plate235 is fastened (e.g., with bolts or other fasteners) to the back wall246. A sealing gasket 250 (shown at FIG. 23) can be provided between themounting flange portion 237 and the back wall 246 to prevent moisturefrom entering the primary compartment 230 of the cabinet 201′. When theplate 235 is mounted to the back wall 246, the enclosure portion 239projects slightly into the primary compartment 230 as shown at FIG. 21.

The secondary compartment 232 is configured to protect and provide readyaccess to a grounding interface 255 used to interconnect the cabinet201′ and shielded cables entering/exiting the cabinet 201′ to ground. Asshown at FIG. 22, the grounding interface 255 includes terminals such asa chassis grounding post 260 and five cable grounding posts 262. In apreferred embodiment, the posts 260, 262 are all externally threadedalong their lengths. The posts 260, 262 all pass through openingsdefined by an electrically conductive bus plate 266. In one embodiment,the bus plate is metal such as copper. Plate contact members such asflanged nuts 264 are threaded on each of the posts 260, 262. When theflanged nuts 264 are threaded down in contact with the bus plate 266,the bus plate 266 functions as an electrical bus that electricallyconnects all of the grounding posts 260, 262 to one another. The chassisgrounding post 260 is preferably electrically connected to ground.Therefore, when all of the posts 260, 262 are electrically connected toone another by the bus plate 266, the posts 260, 262 are all commonlygrounded.

When a field technician needs to direct a locator signal through theshields of one of the cables grounded through the grounding interface,it is desirable to disconnect the shield of the cable from ground and toisolate the selected cable from the other cables. Preferably, this isdone in a easy, non-time consuming manner. In the depicted embodiment, agiven cable can be disconnected from ground by merely backing off theflanged nut 264 corresponding to the cable a sufficient amount so thatthe flanged nut 364 no longer contacts the bus plate 266. With theflanged nut backed off, the selected cable grounding post 262 isdisconnected from the chassis grounding post 260. This allows a locatorsignal to be easily directed through the selected cable grounding post262 to the shield of the cable desired to be located.

FIG. 23 shows an example mounting configuration for the bus plate 266.As shown at FIG. 23, each cable grounding post 262 is electricallyisolated from the bus plate 266 by a first dielectric bushing 270 and iselectrically isolated from the plate 235 by a second dielectric bushing272. The dielectric bushings 270, 272 are preferably generallycylindrical sleeves that fit over the cable grounding posts 262 and fitwithin openings defined by the bus plate 266 and the plate 235,respectively. The first and second post retention nuts 274, 276 arethreaded on the cable grounding posts 262 to lock the posts 262 in placeand prevent axial movement of the posts 262. For example, the postretention nuts 274, 276 are threaded toward one another on the posts 262until the plate 235 is clamped between the nuts 274, 276. Dielectricinsulating washers 277, 278 are mounted between the post retention nuts274, 276 and the plate 235 such that the nuts 274, 276 are electricallyisolated from the plate 235. Additional nuts 280 can be provided on thecable grounding posts 262 for use in connecting wires to the posts. Forexample, one end of a wire can be clamped between nuts 280, 276 whilethe other end is electrically connected (e.g., by a clip) to the metalshield of a cable routed to the fiber distribution hub 200′.

The chassis grounding post 260 is mounted in a slightly differentconfiguration because it is typically not desired to isolate the chassisgrounding post 260 from the bus plate 266 or the plate 235. In thedepicted embodiment, nuts 286, 288 are used to clamp the chassisgrounding posts 260 to the plate 235. No bushings or other isolators areprovided between the plate 235 and the chassis grounding post 260. Thus,the chassis grounding post 260 is electrically connected to the plate235, preferably at all times. An additional nut 289 can be used tosecure a grounding wire to the chassis grounding post 260. The groundingwire 290 preferably runs from the chassis grounding post 260 to ground.A nut 292 is also provided on the chassis grounding post 260 to improveelectrical connection between the bus plate 266 and the chassisgrounding post 260.

In alternative embodiments, a dielectric bushing can also be providedbetween the chassis grounding post 260 and the bus plate 266. In thisway, by backing off flange nut 292, all five of the cable grounding post262 will be disconnected from ground. In this way, a technician may beable to simultaneously direct locating signals through all of the cableshields by directing the signal through one of the cable grounding posts262.

As described above, the chassis grounding post 260 functions to groundthe cabinet 201′. Therefore, an electrical connection preferably existsbetween the plate 235 and the main body of the cabinet 201′. This may beprovided by regions of metal-to-metal contact between the mountingflange portion 237 of the plate 235 and the back wall 246 of the cabinet201′. Alternatively, a wire 294 can also be used to provide anelectrical connection between the main back wall 246 and the plate 235.Similar wires can be used to provide electrical connections between thefront doors 210, 212 and the main body of the cabinet 201′.

Referring again to FIGS. 21 and 23, interior ends of the posts 260, 262are located within the primary compartment 230 of the cabinet 201′. Asshown at FIG. 23, the interior end of the chassis grounding post 260 iselectrically connected to ground 297 (e.g., a metal post pounded in theground) by a wire 251 that extends from the interior end of the post 260through the bottom of the cabinet to ground. Similarly, the interiorends of the two depicted cable grounding posts 262 are electricallyconnected to the shields of cables 298, 299 routed to the fiberdistribution hub 200′. Conventional wires 252, 253 can be used toprovide the electrical connections between the interior ends of theposts 262 and the cables 298, 299. Once the wires 251-253 have beenconnected, there is no need for the wires 251-253 to be later disturbedor disconnected by a field technician. Instead, rather than workinginside the main compartment 230, the cables 298, 299 can be individuallyisolated from outside the primary cabinet 230 within the secondarycompartment 232.

In general use, a field technician arriving at the fiber distributionhub 200′ merely needs to open the secondary door 234 to access thegrounding interface 255. With the secondary door 234 open, thetechnician identifies the cable grounding post 262 corresponding to theburied cable desired to be located. The field technician then loosensthe flanged nut 264 corresponding to the selected cable grounding post262 such that the post 262 is electrically isolated from the bus plate266 and disconnected from ground. With the post 262 electricallyisolated, a locator signal can be transmitted through the cablegrounding post 262 to the shield of the underground cable desired to belocated. After the cable has been located and marked, the flanged nut264 is tightened back down against the bus plate 266 such that the cableis again electrically connected to ground.

FIGS. 24-29 illustrate an alternative secondary compartment 232′ thatcan be accessed from the backside of the cabinet 201′. The secondarycompartment 232′ can be accessed by opening a secondary door 234′ (FIG.27) located on the outside of the cabinet 200′. The secondary door 234′is substantially similar to the secondary door 234 previously describedwith respect to FIGS. 20-23. When the secondary door 234′ is open (seeFIG. 28), access is provided to the secondary compartment 232′, but noaccess is provided to the primary compartment 230 of the cabinet 201′(FIG. 21). Therefore, a field technician can quickly find and enter thesecondary compartment 232′ without disturbing any of the internaltelecommunications components of the fiber distribution hub 200′.

In general, the secondary compartment 232′ is defined by a plate 235′(FIG. 24) having a mounting flange portion 237′ and an enclosure portion239′ (FIG. 25). The mounting flange portion 237′ extends partiallyaround the perimeter of the enclosure portion 239′. The enclosureportion 239′ projects from the mounting flange portion 237′ towards theprimary compartment 230 of the cabinet 200′. The enclosure portion 239′defines a generally rectangular recess that forms the secondarycompartment 232′. The plate 235′ generally mounts to a panel of thecabinet 201′, such as to the back wall 246 (FIG. 20), in substantiallythe same manner as previously described with respect to the plate 235,for example, with fasteners 238′.

The secondary compartment 232′ is configured to protect and provideready access to a grounding interface 255′ used to interconnect thecabinet 201′ and shielded cables entering/exiting the cabinet 201′ toground. In general, the shielded cables are grounded by feedingconventional electrical grounding wires 252′, 253′ from the cables 298,299 (FIG. 21) into the secondary compartment 232′ and couplingelectrical contacts 258′ on the ends of the electrical grounding wires252′, 253′ to the grounding interface 255′.

The electrical grounding wires 252′, 253′ are fed into the secondarycompartment 232′ through openings defined between the enclosure portion239′ of the plate 235′ and the back wall 246 of the cabinet 201″.Support structures 268 typically extend along these openings to enclosethe secondary compartment 232′ to protect the internal components of theprimary compartment 230′ and the internal components of the secondarycompartment 232′. The support structures 268 also guide the electricalwires 252′, 253′ into the secondary compartment 232′. For example, foaminserts 268 having one or more apertures 269 through which theelectrical wires 252′, 253′ can be routed can be provided on one or bothsides of the secondary compartment 232′.

As shown at FIG. 24, the grounding interface 255′ includes terminalssuch as grounding posts 262′. In a preferred embodiment, the groundingposts 262′ are all externally threaded along their lengths. The posts262′ protrude from one or more electrically conductive bus plates 266′(see FIG. 27). In one embodiment, a bus plate 266′ is formed from ametal, such as copper, and the posts 262′ are welded to the bus plate266′. The bus plate 266′ functions as an electrical bus thatelectrically connects the grounding posts 262′ to one another. The busplate 266′ is preferably electrically connected to ground, therebyelectrically connecting all of the grounding posts 262′ to a commonground.

The bus plate 266′ can be electrically connected to ground in a varietyof ways. For example, one of the grounding posts 262′ may serve as achassis grounding post as discussed above with reference to thegrounding interface 255. In other embodiments, the bus plate 266′ ismounted to the plate 235′, for example using bolts 236′, to electricallyconnect the bus plate 266′ and the plate 235′. The plate 235′ is mountedto the cabinet 201′, which can be electrically connected to ground.

FIGS. 26-27 show one example mounting configuration for the bus plate266′. As shown, each cable grounding post 262′ has a base end secured(e.g., welded, press-fit, or otherwise fixed) within an opening definedby the bus plate 266′. First and second nuts 280′, 282′ are provided oneach of the cable grounding posts 262′ for use in connecting the wires252′, 253′ to the grounding posts 262′ (FIG. 28).

For example, an electrical contact 258′ on one end of a wire 252′ can beclamped between the first and second nuts 280′, 282′ as shown in FIG.28. In some embodiments, dielectric insulating washers (not shown) canbe mounted between the electrical contact and the first nut 280′ andbetween the electrical contact and the second nut 282′ to electricallyisolate the electrical contact from the nuts 280′, 282′.

When it is desirable to disconnect the shield of a cable from ground andto isolate the selected cable from the other cables, the electricalcontact 258′ on the wire 252′ is removed from the grounding post 262′.The electrical contact 258′ is removed by first removing the first nut280′ from the post 262′ and then pulling the electrical contact 258′ offof the post 262′. With the electrical contact removed, the selectedelectrical wire 252′ is disconnected from ground while the groundingpost 262′ remains grounded. This allows a locator signal to be easilydirected through the electrical wire 252′ to the shield of the cabledesired to be located.

It will be appreciated that the fiber distribution hub 200 can bemanufactured in a variety of different sizes. However, to promotemanufacturing efficiency, it is preferred for the splitters to bemanufactured with pigtails having uniform lengths. To accommodate thedifferent sizes of fiber distribution hubs, the pigtails are preferablydesigned long enough to work in the largest fiber distribution hubexpected to be used. For the smaller distribution hubs, excess lengthprovided in the pigtails can be taken up by wrapping the excess lengtharound at fiber storage areas. For example, the excess length can bewrapped around spools 252, 254 (see FIG. 7) provided at the top of theswing frame. FIG. 30 shows a swing frame 300′ that utilizes analternative technique for using pigtails of uniform length in differentsized fiber distribution hubs. The swing frame 300′ of FIG. 30 has asplitter module housing 322′ mounted at the front, top left side of theswing frame. To account for different dimensions on different size swingframes, the splitter mount can be mounted at different locations on thetop side of the swing frame. For example, if the standard size pigtailis too short to reach the termination panel on a given swing frame withthe splitter mount located at the far left corner of the top of theswing frame, the splitter mount can be moved to a middle mountinglocation 257, or a right mounting location 259 so that additional lengthis provided to the pigtails.

Referring now to FIGS. 31-34, yet another fiber distribution hub (FDH)200″ having features in accordance with the principles of the presentdisclosure is shown. The fiber distribution hub 200″ includes anotherexample cabinet 201″. The cabinet 201″ has been modified to includecable management panels 220 mounted to the back panel 205 and/or theside panels 204, 206 of the cabinet 201″ (see FIGS. 31 and 32). Thecable management panels 220 can include tie loops 222 that are punchedinto the panels 220. The tie loops 222 allow cable ties to be threadedthere through to secure one or more cables in a fixed position withrespect to the panels 204-206 of the cabinet 201″.

Referring now to FIG. 33, the fiber distribution hub 200″ can mount toan access compartment 1000. The access compartment 1000 includes a toppanel 1002, a bottom panel 1003, a right side panel 1004, a left sidepanel 1006, a back panel 1005, and a front panel 1008. These panels1002-1006 and 1008 define an interior 1020. The top panel 1002 definesan opening configured to align with an opening defined in a bottom panel203′ of the cabinet 201″ when the cabinet 201″ is mounted to the accesscompartment 1000. The bottom panel 1003 defines a cable access opening.

In some embodiments, the fibers of the feeder cable 700 and thesubscriber cable 708 are optically coupled to stub cable fibers from thecabinet 201′ within the access compartment 1000. The optical connectioncan be accessed through an opening defined in the front panel 1008. Theopening in the front panel 1008 is normally covered by a removableaccess panel 1010 or by a door.

Referring now to FIG. 34, the cabinet 201″ houses another swing frame300″. The swing frame 300″ is pivotally mounted within the primarycompartment 230′ (FIG. 31) of the cabinet 201″. In general, the swingframe 300″ has substantially the same component regions as swing frame300 described above. The swing frame 300″ has been modified from swingframe 300, however, to include a frame member 360 mounted to the rear ofthe swing frame 300″ to secure the end of the management leg 420 of eachtermination module 400 opposite the termination leg 410.

The frame member 360 provides support for the termination modules 400and, in particular, supports the weight of the management legs 420 aftercables have been routed through the termination modules 400. The framemember 360 generally extends between the top panel 320 and the bottompanel 330 of the swing frame 300″. In a preferred embodiment, one end361 of the frame member 360 secures to the bottom panel 330 and anopposite end 362 secures to the flange 324 of the top panel 320.

The swing frame 300″ also includes a ramp 365 coupled to the top panel320 of the swing frame 300″. The ramp 365 is positioned adjacent the end329 of the top panel in place of the partial fiber spool 966 and bendlimiter 968 (compare FIG. 34 with FIG. 7). The ramp 365 inhibits thefibers from bending beyond a minimum bend radius when the fiberstransition from the top panel 320 to the front 302 of the swing frame300″. The ramp 365 can also take up (i.e., store) excess slack in thefiber. The ramp 365 can include tabs 368 to inhibit fiber from spillingoff the sides of the ramp 365. In a preferred embodiment, the ramp 365is removable.

The above specification, examples and data provide a completedescription of the manufacture and use of the invention. Since manyembodiments of the invention can be made without departing from thespirit and scope of the invention, the invention resides in the claimshereinafter appended.

1. A telecommunications distribution hub comprising: a cabinet defininga compartment, the cabinet also including one or more main doors foraccessing the compartment; a frame disposed within the compartment toreceive telecommunications equipment, a termination region disposed onthe frame, the termination region being configured to receive atermination panel and a plurality of termination adapters; and asplitter region disposed on the frame, the splitter region beingconfigured to receive a splitter for splitting signals of the incomingfiber to a plurality of splitter fibers, the splitter region beinglocated above the termination panel on the frame; and a ramp disposed ata top of the frame, the ramp being sized and oriented so that at least aportion of the splitter fibers are routed along a splitter fiber routingpath extending from the splitter region, up and over the ramp that has ahighest point located above the splitter region, and down past thesplitter region towards the termination region, the ramp inhibiting thesplitter fibers from bending beyond a minimum bend radius. 2-11.(canceled)
 12. The telecommunications distribution hub of claim 1,further comprising: a second compartment that can be accessed from anexterior of the cabinet without accessing the compartment; and aplurality of cable grounding terminals having first ends accessible fromthe compartment and second ends accessible the second compartment. 13.The telecommunications distribution hub of claim 1, further wherein theframe includes a swing frame pivotally mounted within the compartment.14. The telecommunications distribution hub of claim 13, wherein thetermination region is disposed at a front of the swing frame.
 15. Thetelecommunications distribution hub of claim 14, wherein the splitterregion is disposed at the top of the swing frame.
 16. Thetelecommunications distribution hub of claim 15, wherein the rampextends upwardly from the top of the swing frame.
 17. Thetelecommunications distribution hub of claim 16, wherein the ramp islocated at an opposite side of the swing frame from the splitter region.18. The telecommunications distribution hub of claim 13, wherein thesplitter fiber routing path includes at least a portion that extendslaterally across a front side of the swing frame to the terminationregion.
 19. The telecommunications distribution hub of claim 18, whereinthe splitter fiber routing path extends downwardly from the ramp alongthe front side of the swing frame to a spool structure, around the spoolstructure, and then back upwardly along the front side of the swingframe before being routed laterally across the front side of the swingframe to the termination region.
 20. The fiber distribution hub of claim19, wherein the swing frame defines a vertical channel extending alongthe front side of the swing frame and on a side of the terminationregion opposite a swing frame pivot mounting location, wherein thevertical channel is part of the splitter fiber routing path so that thesplitter fibers are routed at least partially down the swing frame frontside when the splitter fibers extend downwardly towards a bottom of thecompartment.
 21. The telecommunications distribution hub of claim 13,wherein the swing frame is movable between a first position where theswing frame is inside the compartment and a second position where theswing frame extends at least partially outside the compartment.
 22. Thetelecommunications distribution hub of claim 13, wherein the ramp isremovable from the swing frame.
 23. The fiber distribution hub of claim13, wherein at least a portion of the plurality of splitter fibers arerouted along a second splitter fiber routing path located on the swingframe, the second splitter fiber routing path extending from thesplitter region, across a swing frame top surface, over a bend radiuslimiter which is substantially flush with the swing frame top surface,at least partially down the swing frame front side and laterally acrossat least a portion of the front side of the swing frame to thetermination region.
 24. The telecommunications distribution hub of claim1, wherein the ramp is sized to store excess slack in the splitterfibers.
 25. The telecommunications distribution hub of claim 1, whereinthe ramp includes tabs to inhibit the splitter fibers from spilling offthe sides of the ramp.